Pebble bed modular reactor

Alternative reactor types are possible for the VHTR. China s HTR-10 [35] and South Africa s pebble bed modular reactor (PBMR) [41] adopted major elements of pebble bed reactor design including fuel element from the past German experience. The fuel cycles might be thorium- or plutonium-based or potentially use mixed oxide (MOX) fuel. 

In many poor African states there is no electricity grid or coverage is very limited, but there are often dispersed locations that could use significant amounts of energy—an aluminum smelter in Mozambique, for example. A nuclear power plant could provide electricity, but South African efforts to introduce a new small-scale technology, the Pebble Bed Modular Reactor, which is far safer than previous reactors and can be controlled and shut down remotely, are being hampered by international rejection of older nuclear technologies.12 (See Cohen, this volume, about nuclear power science and politics in the United States.)... 

K. Renun, A New Erafor Nuclear The Development of the Pebble Bed Modular Reactor (Cambridge European Science and Environment Forum [ESEF], 2000). Available atwww.scienceforum.net. 

Pebble-Bed Modular Reactor (PBMR) A nuclear reactor technology that utilizes tiny silicon carbide-coated uranium oxide granules sealed in pebbles about the size of oranges, made of graphite. Helium is used as the coolant and energy transfer medium. This containment of the radioactive material in small quantities has the potential to achieve an unprecedented level of safety. This technology may become popular in the development of new nuclear power plants. 

TRANSIENT MODELLING OF S-l CYCLE THERMOCHEMICAL HYDROGEN GENERATION COUPLED TO PEBBLE BED MODULAR REACTOR... 

Transient modelling of sulphur-iodine cycle thermochemical hydrogen generation coupled to pebble bed modular reactor... 

Several reactors are candidates for use as a high temperature heat source for the S-I cycle. Candidates include the modular helium reactor (MHR) and pebble bed modular reactor (PBMR). One of the most thoroughly investigated candidates is the PBMR. Recent work has been performed in benchmarking the THERMIX code to the PBMR-268 design (Reitsma, 2004 Seker, 2005). 

Safely implementing a thermochemical nuclear hydrogen generation scheme requires a robust understanding of the interaction between the nuclear plant and the chemical plant. In turn, this requires robust models of the chemical plant, reactor thermal-hydraulics and reactor physics. Efforts have been conducted in both the transient modelling of the sulphur-iodine (S-I) and hybrid sulphur (HyS) thermochemical cycles, as well as coupling to models of the pebble bed modular reactor (PBMR-268) (Brown, 2009). 

In terms of safety, two issues are regularly debated. First, the issue of nuclear waste and, second, concerns over potential terrorist attacks on nuclear power plants. The first objection may be overcome through the introduction of new types of power plants, such as the pebble-bed modular reactor.This type of reactor uses graphite balls flecked with tiny amounts of uranium, rather than conventional fuel rods. With the fuel encased in graphite and impermeable silicon carbide, the theory is that the waste should be relatively easy to dispose of.The terrorism fears are less easily addressed and may ultimately stall the construction of new plants in countries such as the U.S., where these worries are greatest. 

Ion, S. et al., Pebble Bed Modular Reactor The First Generation IV Reactor to Be Constructed, paper presented at the World Nuclear Association Annual Symposium, London, September 3-5. 

Pebble bed modular reactor - South Afnca M. Fox, E. Mulder... 

New concepts based on passive safety presently under study are the Pebble Bed Modular Reactor (PBMR - gas cooled, high temperature, helium operated, direct cycle turbine generators) supported by an international group based in South Africa, the IRIS reactor (a PWR with steam generators integrated in the reactor pressure vessel) and the already mentioned APIOOO. Other concepts still under study but already proposed exist... 

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